Monday [11/10/2021] Flashcards
What is a FAST scan used for? [1]
To investigate the presence of free fluid
What is the trimodal death distribution? []3
Following trauma there is a trimodal death distribution:
Immediately following injury. Typically as result of brain or high spinal injuries, cardiac or great vessel damage. Salvage rate is low.
In early hours following injury. In this group deaths are due to phenomena such as splenic rupture, sub dural haematomas and haemopneumothoraces
In the days following injury. Usually due to sepsis or multi organ failure.
Example thoracic injuries [4]
Simple pneumothorax
Mediastinal traversing wounds
Tracheobronchial tree injury
Haemothorax
Blunt cardiac injury
Diaphragmatic injury
Aortic disruption
Pulmonary contusion
Mx of simple pneumothorax [2]
Simple pneumothorax insert chest drain. Aspiration is risky in trauma as pneumothorax may be from lung laceration and convert to tension pneumothorax.
Mx of mediastinal traversing wounds [2]
These result from situations like stabbings. Exit and entry wounds in separate hemithoraces. The presence of a mediastinal haematoma indicates the likelihood of a great vessel injury. All patients should undergo CT angiogram and oesophageal contrast swallow. Indications for thoracotomy are largely related to blood loss and will be addressed below.
Mx of tracheobronchial tree injuries [2]
Unusual injuries. In blunt trauma most injuries occur within 4cm of the carina. Features suggesting this injury include haemoptysis and surgical emphysema. These injuries have a very large air leak and may have tension pneumothorax.
Mx of cardiac contusions
Usually caused by laceration of lung vessel or internal mammary artery by rib fracture. Patients should all have a wide bore 36F chest drain. Indications for thoracotomy include loss of more than 1.5L blood initially or ongoing losses of >200ml per hour for >2 hours.
Mx of diaphragmatic injuries
Usually cardiac arrhythmias, often overlying sternal fracture. Perform echocardiography to exclude pericardial effusions and tamponade. Risk of arrhythmias falls after 24 hours.
Mx of truamatic aortic disruptions
Commonest cause of death after RTA or falls. Usually incomplete laceration near ligamentum arteriosum. All survivors will have contained haematoma. Only 1-2% of patients with this injury will have a normal chest x-ray.
Mx of pulmonary contusions
Common and lethal. Insidious onset. Early intubation and ventilation.
Mx of diaphragmatic injuries [1]
Usually left sided. Direct surgical repair is performed.
Which injuries are common in abdominla trauma? [1]
Deceleration injuries are common.
How to manage abdominal trauma [5]
Deceleration injuries are common.
In blunt trauma requiring laparotomy the spleen is most commonly injured (40%)
Stab wounds traverse structures most commonly liver (40%)
Gunshot wounds have variable effects depending upon bullet type. Small bowel is most commonly injured (50%)
Patients with stab wounds and no peritoneal signs up to 25% will not enter the peritoneal cavity
Blood at urethral meatus suggests a urethral tear
High riding prostate on PR = urethral disruption
Mechanical testing for pelvic stability should only be performed once
Advantage of a CT scan for abdiominla trauma
Most specific for localising injury; 92 to 98% accurate
Disadvantage of CT abdomen for trauma
Location of scanner away from facilities, time taken for reporting, need for contrast
Adv and dis for USS for abdominal trauma [2]
Early diagnosis, non invasive and repeatable; 86 to 95% accurate
Operator dependent and may miss retroperitoneal injury
Se of digoxin [1]
Loss of appetite and anorexia
What type of drug is digoxin? [2]
Digoxin is a cardiac glycoside now mainly used for rate control in the management of atrial fibrillation
How does digoxin work? [2]
As it has positive inotropic properties it is sometimes used for improving symptoms (but not mortality) in patients with heart failure.
MoA of digoxin [3]
decreases conduction through the atrioventricular node which slows the ventricular rate in atrial fibrillation and flutter
increases the force of cardiac muscle contraction due to inhibition of the Na+/K+ ATPase pump. Also stimulates vagus nerve
digoxin has a narrow therapeutic index
Monitoring of digoxin [2]
digoxin level is not monitored routinely, except in suspected toxicity
if toxicity is suspected, digoxin concentrations should be measured within 8 to 12 hours of the last dose
Features of digoxin toxicity [3]
generally unwell, lethargy, nausea & vomiting, anorexia, confusion, yellow-green vision
arrhythmias (e.g. AV block, bradycardia)
gynaecomastia
Precipitating factors for digoxin toxicity [5]
classically: hypokalaemia
increasing age
renal failure
myocardial ischaemia
hypomagnesaemia, hypercalcaemia, hypernatraemia, acidosis
hypoalbuminaemia
hypothermia
hypothyroidism
drugs: amiodarone, quinidine, verapamil, diltiazem, spironolactone (competes for secretion in distal convoluted tubule therefore reduce excretion), ciclosporin. Also drugs which cause hypokalaemia e.g. thiazides and loop diuretics
Mx of digoxin toxicity [3]
Digibind
correct arrhythmias
monitor potassium
How does hypokalaemia cause digoxin toxicity? [2] -> important
digoxin normally binds to the ATPase pump on the same site as potassium. Hypokalaemia → digoxin more easily bind to the ATPase pump → increased inhibitory effects
can Digoxin toxicity occur within the therapeutic range? [2]
Toxicity may occur even when the concentration is within the therapeutic range. The BNF advises that the likelihood of toxicity increases progressively from 1.5 to 3 mcg/l.
. A 72-year-old man presents with a large nodule on his face. It is friable. There is no regional lymphadenopathy. He is lost to follow up and re-attends several months later. On this occasion the lesion has been noted to resolve with scarring.
Keratoacanthoma71%
Keratoacanthomas may reach a considerable size prior to sloughing off and scarring.
- A 22-year-old woman is troubled by intensely itchy crops of blisters on her arms and legs. On examination she is malnourished and she has papulovesicular eruptions over her elbows and knees.
Dermatitis herpetiformis79%
Dermatitis herpetiformis is seen in association with coeliac disease.
A 30-year-old man cuts the corner of his lip whilst shaving. Over the next few days a large purplish lesion appears at the site which bleeds on contact.
Pyogenic granuloma76%
Pyogenic granulomas often appear at sites of trauma.
Features of BCC [5]
Most common form of skin cancer.
Commonly occur on sun exposed sites apart from the ear.
Sub types include nodular, morphoeic, superficial and pigmented.
Typically slow growing with low metastatic potential.
Standard surgical excision, topical chemotherapy and radiotherapy are all successful.
As a minimum a diagnostic punch biopsy should be taken if treatment other than standard surgical excision is planned.
Features of SCC
Again related to sun exposure.
May arise in pre - existing solar keratoses.
May metastasize if left.
Immunosupression (e.g. following transplant), increases risk.
Wide local excision is the treatment of choice and where a diagnostic excision biopsy has demonstrated SCC, repeat surgery to gain adequate margins may be required.
Main diagnostic criteria for malignant vs minor criteria for MM [4]
The main diagnostic features (major criteria):
Change in size
Change in shape
Change in colour
Secondary features (minor criteria)
Diameter >6mm
Inflammation
Oozing or bleeding
Altered sensation
Tx of malignant carcinomas [2]
Suspicious lesions should undergo excision biopsy. The lesion should be removed in completely as incision biopsy can make subsequent histopathological assessment difficult.
Once the diagnosis is confirmed the pathology report should be reviewed to determine whether further re-excision of margins is required (see below):
What is Kaposi Sarcoma? [4]
Tumour of vascular and lymphatic endothelium.
Purple cutaneous nodules.
Associated with immuno supression.
Classical form affects elderly males and is slow growing.
Immunosupression form is much more aggressive and tends to affect those with HIV related disease.
Features of Dermatitis Herpetiformis
Chronic itchy clusters of blisters.
Linked to underlying gluten enteropathy (coeliac disease).
Features of dermatofibroma
Benign lesion.
Firm elevated nodules.
Usually history of trauma.
Lesion consists of histiocytes, blood vessels and fibrotic changes
Features of pyogenic granuloma
Overgrowth of blood vessels.
Red nodules.
Usually follow trauma.
May mimic amelanotic melanoma
Features of acanothsis nigricans
Brown to black, poorly defined, velvety hyperpigmentation of the skin.
Usually found in body folds such as the posterior and lateral folds of the neck, the axilla, groin, umbilicus, forehead, and other areas.
The most common cause of acanthosis nigricans is insulin resistance, which leads to increased circulating insulin levels. Insulin spillover into the skin results in its abnormal increase in growth (hyperplasia of the skin).
In the context of a malignant disease, acanthosis nigricans is a paraneoplastic syndrome and is then commonly referred to as acanthosis nigricans maligna. Involvement of mucous membranes is rare and suggests a coexisting malignant conditio
A 55-years-old man presents to the emergency department with severe epigastric pain and fever. He looks unkempt and affirms to be drinking 40 units of alcohol per week. He presented to the emergency department after suffering from the symptoms for two days, due to a phobia of hospitals.
Given the most likely diagnosis, which of the following is the single best investigation to order?
Serum lipase has a longer half-life than amylase when investigating suspected acute pancreatitis and may be useful for late presentations > 24 hours
PP of acute pancreatitis [2]
- autodigestion of pancreatic tissue by the pancreatic enzymes, leading to necrosis
Features of acute pancreatitis [4]
severe epigastric pain that may radiate through to the back
vomiting is common
examination may reveal epigastric tenderness, ileus and low-grade fever
periumbilical discolouration (Cullen’s sign) and flank discolouration (Grey-Turner’s sign) is described but rare
Ix for pancreatitis [6]
serum amylase
- raised in 75% of patients - typically > 3 times the upper limit of normal
- levels do not correlate with disease severity
- specificity for pancreatitis is around 90%. Other causes of raised amylase include: pancreatic pseudocyst, mesenteric infarct, perforated viscus, acute cholecystitis, diabetic ketoacidosis
serum lipase
- more sensitive and specific than serum amylase
- it also has a longer half-life than amylase and may be useful for late presentations > 24 hours
imaging
a diagnosis of acute pancreatits can be made without imaging if characteristic pain + amylase/lipase > 3 times normal level
however, early ultrasound imaging is important to assess the aetiology as this may affect management - e.g. patients with gallstones/biliary obstruction
other options include contrast-enhanced CT
When can diagnosis of acute pancreatitis be made w/o imaging? [2]
a diagnosis of acute pancreatits can be made without imaging if characteristic pain + amylase/lipase > 3 times normal level
Why is early USS important in a patient with acute pancreatitis? [2]
however, early ultrasound imaging is important to assess the aetiology as this may affect management - e.g. patients with gallstones/biliary obstruction
Common factors indicating severe pancreatitis [5]
The specifics of each scoring system will not be repeated here. However, some common factors indicating severe pancreatitis include:
age > 55 years
hypocalcaemia
hyperglycaemia
hypoxia
neutrophilia
elevated LDH and AST
Erythema mulitforme [target lesions]
Erythema nodosum
Erythema gryatum
Plymorphic eruption of pregnancy
Tuberous sclerosis
Cafe au lait spots [seen in TS and NF]
Lichen planus
Lichen slceorsis
Lichen sclerosis
Actinic keratosis
Multiple myeloma
SCC
BCC
Chronic plaque psoriasis
Naevus
Lung collpase
Malar rash in SLE
Compare NMS to SS
Grade 3 VUR
Pityriasis rosea
pityriasis rosea
Guttate psoriasis
Differentiating between gutttate psoriasis and pityriasis rosea
Seen in reactive arthritis
